Refrigerating apparatus



April 20 1926. 1,581,103

R. W. DAVENPORT REFRIGERATING APPARATUS Original Filed April 11, 1924 INVENTOQ Patented Apr. 20, 1926.

UNITED STATES 1,581,103 PATENT OFFICE.

RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN.

REFRIGERATING APZELARATUS.

Application filed April 11, 1924, Serial no. 705,809. Renewed September 16, 1925.

To all whom it may concern. I

Be it known that I, RANSOM W. DAVEN- roRT, a citizen of the United States, residing at Detroit, in the county of Wayne and the State of Michigan, have invented new and useful Improvements in Refrigerating Apparatus, of which the following is a specification.

This invention is an improvement in refrigerating apparatus and has among its objects the provision of machines and apparatus particularly adapted to employ as part of the working substance, hydrocarbons, sul phur di-oxide, or other agents which tend to combine with or dissolve ordinary lubricants and injure or dcstory their lubricating value. h

All refrigerating systems must employ a pump. The form most generally used is the reciprocating or piston compressor, and it is considered essential that some lubricant be supplied to its working parts. It is the common practice'to soconstruct and arrange the compressor that the crank case is fully enclosed and is under the same pressure as the evaporator, i. e., the low-side pressure. The oil in the crank case is therefore under that pressure also, and its vapor mingles with that of the refrigerant. It is of course impossible vvith such constructions and arrangements, to permit any liquid refrigerant to be present in the crank case even if it were desired to use it as the lubricant, since the compressor itself would then become the re frigerator. r

On the contrary, it is impossible with the commonly known constructions and arrangements, to put the crank case under high-sideor condenser pressure with a view to using the refrigerant ltself as the lubricant, with- I out suffering agreat loss in power since the suction stroke would then have to. be made against the high pressure, and the power required would be practically all lost. Nor would it wholly overcome this disadvantage to use a common two-cylinder construction, for while theoretically the pressures on the backs of both pistons are equal, in fact the loss is still prohibitive due to the excess bearing loads and also to the unavoidable differ- "ence in the velocities of the separate pistons known.

K vantages 1n the use of 011s are commonly A One of the principal objects of this pressible to use the refrigerating liquid itself as the lubricant, and eliminating one of the mostpserious problems'in the refrigerating art.

. Another object of my invention is to provide a pump or compressor of large'volumetric displacement yet of moderate size for use in such circumstances as require a compact machine. For example, in refrigeratlng systems employing refrigerants of low vapor tensions like water or alcohol, the volume of va or which must be pumped is so considerable that, heretofore the reciprocating pump has been considered impracticable on account of its size and weight.

Other objects of my invention will appear hereafter.

The accompanying drawing is a view,

partly in section, of a'preferre'd form of my invention, showingits operative relation to the condenser, expander etc.

In the accompanying drawing, 1 is a prime .mover geared to the crank-shaft 2 of the compressor or pump. The piston3, having packing rings H and 55 at bothends, is reciprocated by the shaft 2 through the linkage or connecting rod 6, bearing in the piston at 7 between the packings 4 and 5. The cylinder of the pump is adaptedto form a housing 8 for the shaft and linkage. At 9 is shown a condenser connected in the usual manner to the expander 11 through the expansion valve 10,the whole comprising the well known compressor-condenser-expander circuit. N

Thepipe 12 and reservoir 13 connect the condenser with the housing. or crank case 8 of the compressor, and may be arranged .to feed liquid from the condenser into the pump in any well known manner.

My invention operates substantially as follows: Upon starting the motor 1, the

piston is reciprocated by shaft 2, linkage 6 and bearing 7 and pressure is developed in condenser 9 which is transmitted through '12 and 13 back into the crank case 8,. But

since the piston 3 simply ,moves as a whole and nothing moves in or out of the crank case, there is absolutely no change of volume therein, and consequently neither the pressure nor the bearing load is altered in the least. The condensate formed in 9 is now fed back, a proper amount at a time, through the pipe 12, and finds its way to the various rubbing surfaces. The amount may be regulated in any suitable manner well known to the art, as by a needle valve or other sight feed device.

It-will be clear that I have provided a system whereby oils may be eliminated from the apparatus entirely. It is also obvious that the apparatus may be very compact,

thus enabling me to use refrigerants of low vapor tension, if desired.

I donot desire to claim as my invention any specific means for operating a pump piston; nor do I claim any specific'means for lubricating a compressor; for by the aid of the principles set forth above, anyone skilled in the art may easily, embody my invention in a varietyofequivalent forms.

, I claim:

1. In a refrigerating system having a compressor, a condenser, and anevaporator,

. means for conducting fluids from said con:

denser into the crank case of said compressor to lubricate theparts thereof.

2. In a-refrigerating system having a compressor, a condenser, and an evaporator, a pipe connecting said condenser tothe crank case of said compressor whereby fluid from the condenser is utilized for the lubrication of the compressor.

means for collecting at least a portion of the condensate of said condenser, and means 3. In a refrigerating system having a com-- pressor, a condenser, and an j evaporator,

for conducting said condensate into the crank case of said compresson,

4. Apparatus forming a closed cycle sys-- tern for producingrefrigeration comprising a compressor, a condenser, an evaporator, said parts being suitably connected together, a reservoir connected to the lower portion of said condenser for receiving a part of the condensate thereof, and means including a pipe extending from said reservoir to the crank case of said compressor for conducting condensate in limited amount thereto to act as a lubricant for the Working parts of said compressor.

5. A refrigeratingcompressor having a. piston chamber, a piston therein, a crankcase inclosing movable parts for operating the compressor, and a fluid connection be tween said crankcase and the discharge line of said compressor.

6. A refrigerating compressor having a piston chamber, a piston reciprocable therein, a crankcase inclosing movable parts for actuating said piston, and a pipe connecting said crank case with the discharge port of said compressor.

7. Combined ina refrigerating com pressor having a reciprocating piston and a crankcase, a piston packing adjacent each end of said piston; a bearing in said piston located between said piston packings; a crankshaft supported within said crankcase transversely of said piston; linkage withinv said crankcase connecting said crankshaft and said bearing; and a pipe connecting said crankcase with the discharge port of said compressor.

8. In a compressor condenser-expander type of refrigerating apparatus including a compressor having a reciprocating piston and a crankcase; packings adjacent the ends of said piston; means connected to said piston between said packings adapted to reciprocate the piston said reciprocating means being suitably disposed within said crank case; and means for feeding liquid from the aforementioned condenser into said crankcase.

RANSOM W. DAVENPORT. 

